1. Field of the Invention
The present invention relates to a retractable outer mirror attached to or near a side door of an automobile.
2. Description of the Related Art
A typically-used retractable outer mirror is attached to a lateral side of an automobile, and its mirror assembly rotates between two positions. The two positions are: a use position at which a mirror surface is at substantially right angles to the lateral side of the automobile; and a retracted position at which the mirror surface is substantially parallel to the lateral side of the automobile.
For example, Japanese Laid-Open Patent Application, Publication No. 2001-287593 (to be referred to as Patent Document 1 hereinafter) discloses an outer mirror which includes: a shaft vertically arranged on a base section; and a frame attached to the mirror base so as to freely rotate about the shaft. The frame is inserted into the shaft and is energized toward the mirror base by a coil spring, one end of which is in contact with a top end of the shaft. Such a configuration allows the frame (the mirror assembly) to smoothly rotate without rattling.
The shaft includes: a plate-like base section; and a cylindrical shaft section vertically arranged on the base section. The base section includes a plurality of stoppers each protruding thereon and having different size and shape. The stopper performs positioning of the frame (the mirror assembly) and also serves as a clutch mechanism by coming in contact with a plate stopper. When external force acts on the mirror assembly, the clutch mechanism allows the external force to escape and a shock to be absorbed, by making the mirror assembly fall down on a front or a rear side of the automobile. A plurality of protrusions into which a plate clutch is inserted are formed around the cylindrical shaft section.
Shape, size, number, or the like of the stoppers and protrusions formed in the shaft varies according to not only a type of the automobile and whether the above components are attached on a right or left side of the vehicle but also a falling degree of the mirror assembly, a configuration of the clutch mechanism, and whether the outer mirror is retracted by electric motor or manually. This makes it difficult for the shaft used in one place to be used in another, which is not advantageous to a reduction in cost of manufacturing.
Japanese Laid-Open Patent Application, Publication No. 2001-334874 (to be referred to as Patent Document 2 hereinafter) discloses an outer mirror which includes: a right/left use shaft having a plate-like base section and a cylindrical shaft section vertically arranged on the base section; and a first stopper fitted into a through hole formed on the base section, from below the right/left use shaft.
Aright side outer mirror and a left side outer mirror have respective first stoppers different from each other. However, since the right/left use shaft is formed symmetrically, it can be used for both the right side outer mirror and the left side outer mirror. This means that a shaft used for the right side outer mirror can also be used for the left side outer mirror, thus enabling a shared use of components necessary for manufacturing the right and left outer mirrors, which can reduce cost of manufacturing.
A shaft has a configuration in which a convex portion of a first stopper is inserted into a through hole formed on the base section, from below the base section of the right/left use shaft. Thus, if a shape or a position of, for example, the convex portion of the first stopper is modified according to a configuration of a clutch mechanism, a shape or a position of the through hole of the right/left use shaft has to be changed. That is, the inventions according to Patent Document 2 have difficulties in using the same shaft in different types of automobiles or clutch mechanisms, though the same shaft can be used for both the right and left side outer mirrors. This is because modification of a configuration such as a shape of one of the right/left use shaft and the first stopper affects a configuration of the other.
In light of the above-mentioned problems, the present invention has been made in an attempt to provide a shaft structure of a retractable outer mirror enabling a shared use of components necessary for manufacturing outer mirrors regardless of an automobile type, a configuration of a clutch mechanism, whether an outer mirror is retracted by electric motor or manually, or the like.